Fine Tuning
SSOE Inc. is one of the country’s few architectural firms thoroughly invested in how schools sound as well as how they look. Their latest project is a new $45 million district campus for the River Valley School District in Marion, Ohio, anchored by the $17 million, 121,000-square-foot River Valley High School.
Beyond providing specialized choral, instrumental, and band practice rooms for River Valley’s highly competitive music programs, SSOE also took a tailored approach to the different needs of classrooms, corridors, faculty lounges, counseling rooms, and offices, lowering reverberation times and reducing background noise.
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PROJECT DATA River Valley High School-Marion, Ohio |
Charles Stark, an architect who is nationally recognized for his long career in acoustics, joined SSOE in 1999 after running his own practice for 25 years. He has designed music schools for numerous universities, including Ithaca College, Florida Southern University, and Bowling Green State University, but is also attuned to everyday classroom auditory needs.
Among the acoustic techniques employed at River Valley are classroom walls that extend above ceiling height, strategically placed restrooms and mechanical systems, and gymnasiums and cafeterias that take full advantage of noise-abatement products currently available on the market.
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| The band room was designed to allow students to play at the same volume as they would outdoors. |
"Twenty years ago, almost no architects even thought about acoustics," says Stark, who has studied acoustics for 40 years and believes the subject remains under-taught in architecture schools. Stark is a forerunner of acoustically-enhanced education whose career spans to an era that increasingly accepts acoustics as a cornerstone of education design.
Acoustic Control
River Valley High School is only an anchor for the larger district campus. The Quandel Group Inc. provided construction management services for the complex, which also includes a 65,000-square-foot middle school, two 50,000-square-foot elementary schools, and a 33,000-square-foot administration building.
New classroom acoustics cater to the way children’s hearing develops; limiting reverberation and background noise is most critical in elementary and middle schools. "Their auditory organs are not as well developed," Charles Stark says of young children. "If you have a long reverberation time, the consonants are shorter and the vowels are longer, so children mistake words."
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| Ceilings and carpeting alone won’t provide optimal acoustics. Wall panels with special fabric are used in sensitive areas, such as the media center. |
Reverberation time is the duration it takes for sound to decay to 60 decibels. While most classrooms have a reverberation time of 0.9 to 1.0 second, reducing the time to a half second is considered optimal. "It takes a lot of absorption to bring it down to a half second, but you can tell the difference between 0.5 and 1.0 second. It’s dramatic."
Such voices are rising above the proverbial din. A new acoustical standard was approved in June 2002 by the American National Standards Institute (ANSI) and published soon after by the Acoustical Society of America as ANSI S12.60-2002, Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools. The standard recommends a classroom reverberation time of 0.6 seconds.
At every grade level, River Valley’s classrooms meet or exceed this standard in all four campus schools. "If you just put in normal acoustic tile ceilings and normal furnishings, I guarantee you won’t meet that standard," Stark asserts. He also acknowledges that most architecture firms don’t have the resources to hire an acoustician, but believes many sound-dampening goals can be achieved without a trained consultant.
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| Acoustic block and acoustic roofdeck work in conjunction to dampen sound in gymnasiums. |
Stark’s advice? "Do not make all the dimensions of your room equal. For instance, you can change the 30′ by 30′ room dimension to 29′-6" by 31′-7", or change the ceiling height. It’s simple and it doesn’t cost anything to do it that way."
Rather than ending wall structures at the ceiling, SSOE designs the walls between classrooms to reach the structure above, avoiding sound transfer from the next classroom through ceiling breaks. Such measures are necessary not only for children, but also for teachers.
"In order to be heard, a teacher has to raise their voice around nine or 10 decibels above the background noise. And that means that, all day, teachers are straining when they’re talking," Stark notes. "It’s surprising how much energy that takes, and those teachers go home exhausted."
It’s also a mistake to think only of the teacher standing in front of the class, the acoustically ascending end. Kids need to hear other students speaking and teachers often walk to the side, so classrooms have to distribute sound uniformly.
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The high school auditorium is the school’s acoustic centerpiece, used for district-wide performances and assemblies. While the acoustic needs of all performance types are addressed, the space is tuned with the spoken word in mind. |
Mechanical systems are a major source of background noise. "All the mechanical mezzanines at River Valley were zoned to not interfere with classrooms or other sensitive environments," says Kirk Keaffaber, project architect for SSOE. "One sits over the locker room, one sits over restrooms, and the third sits over the kitchen, so you don’t get the noise or the vibration."
The Quandel Group’s team built mechanical rooms with solid, dense walls reaching to the other side of the roof deck to prevent sound from bouncing off the underside of the deck. These walls are packed with acoustical insulation to fill cracks, while vibrating equipment is placed on an isolation pad supported by springs or neoprene.
Pipes extending from pumps are hung with spring-loaded hangers so pipe vibrations don’t radiate through the walls or through the pipe. Pipes running through the walls are sealed with a resilient acoustical caulking. "In other cases, we even isolate the entire floor of an equipment rooms and place it on little neoprene pads, so the whole floor of the room is a sound dampening device," says Stark.
SSOE controls noisy school corridors by using acoustic ceiling tile superior to what is typically used. Tile appearance should not always take precedence over sound, and SSOE evaluates tile on all frequencies because most ratings systems focus only on frequencies in the center range, leaving important frequencies at either end of the scale with an unequal place in the equation.
Sound Concerns
River Valley High School is proof that a project under typical time and cost pressures can pay close attention to acoustics without slowing the schedule-because River Valley was anything but typical, having been completed on an accelerated timeline in response to grave environmental concerns.
In 1963, the old school complex was sited above a former U.S. Army Depot that contained harmful chemicals. In 2000, the Ohio Department of Health concluded that leukemia rates were significantly high among the school’s graduates. The Ohio School Facilities Commission (OSFC), a government agency that facilitates school planning efforts and allocates state matching funds for construction, added River Valley to the agency’s Extreme Environmental Contamination Program.
Moving the project up the waiting list set the stage for a successful local bond measure and additional federal assistance. The number of agencies involved might have hampered another project, but after only 16 months of construction, River Valley High School was completed in August 2003, emerging from the crisis on a safe farmland site.
The community around Marion was thrilled with the new facility. Local athletic boosters helped the district acquire a 100-acre tract to accommodate a baseball/softball quad with four fields, a track/soccer facility, and a new football stadium. Junior varsity teams, community soccer players, and the marching band also have field space available to them.
Keaffaber says one challenge in creating a campus serving multiple grade levels was appropriately segregating the varied vehicle traffic of bus loops, parent drop-offs, and student cars. "You’re dealing with junior drivers, so you try to make parking as simple and direct as you possibly can," says Keaffaber.
To make a flat site more dynamic and give the complex a stronger presence, the entire complex is rotated 15 degrees off square. The four schools are distinguished with primary and accent colors, and manufactured stone was used to announce entrances. Inside, a non-institutional look resonates with acoustical accents.
Noise is abated throughout the River Valley district campus, but the high school is the acoustic centerpiece, housing a 700-seat auditorium that serves all four schools. SSOE brought its subtle understanding of the different performances and presentation needs, from opera to bands, and wrapped it all in one space.
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PRODUCT DATA Auditorium/Assembly: Irwin Seating Co. Brick/Masonry: Beldon Brick Acoustic Products Carpet and Flooring Washroom Equipment/Supplies Physical Education Equipment Miscellaneous |
"When people say a room has perfect acoustics, you always have to ask, ‘For what?’ It’s not the same in an auditorium for speech, for music, or sound-reinforced movies," says Stark. "You want as much sound power to reach the audience as you possibly can, so the music has life to it, but I tune my school auditoriums a little more toward the spoken word, because that’s a little more critical."
SSOE has been making good use of acoustical roof deck in high-volume spaces, with Stark noting that 20 different kinds of decking can be offered by a single manufacturer. "It’s a perforated deck with a sandwich of insulation, and between the acoustic block and the roof decking you significantly reduce the amount of noise within the gymnasium space," Keaffaber says.
Acoustic blocks have slots that form a Helmholtz resonator which traps sound, a quality sometimes enhanced with a fiberglass, better distributing sound absorption throughout the space and fostering a broader range of frequencies than were formerly available. Stark suggests placing acoustic block above the 12 foot mark. "The kids always want to stick pennies and whatnot in these slots, so you get them up where they can’t get at them," he notes.
Moving to the music rooms, River Valley High School has a specially-tuned space for vocal, orchestra, and band practice. The school’s pitched roof offers a range from 20 to 35 feet in height for a full sound.
"It’s not how many musicians you can fit in there, it’s how many musicians you can fit acoustically so that the room sounds good," says Stark.
Flat floors rather than permanent risers were created for flexibility to arrange the musicians or singers. And because young voices can’t project as much, River Valley’s choral rooms were made more reverberant than a college choral room. Stark prefers to include one wall that’s very absorbent to mute the sound a little bit, allowing rehearsing band students to exert as much wind pressure as they would outdoors.
Counseling and administration areas have thick masonry walls to preserve privacy and confidentiality. In addition, toilets are kept far from these sensitive spaces, in most cases beside storage spaces. "It’s a matter of planned arrangement to avoid conflicts of two noisy rooms. The gym next to the auditorium is not a good idea," says Stark.
Also commonly overlooked are cafeteria acoustics. "Teachers often don’t want to go in and monitor the lunch room because it gives them a headache," says Stark. "We have wall absorption in River Valley’s cafeteria, we’ve got a good quality acoustic tile ceiling, and we have some coffered sections that diffuse the sound. You can’t do much on the floor, but you can do as much as you can on the walls and ceilings and the teachers will appreciate that."